Kinetics and reusability of Zr/CaO as heterogeneous catalyst for the ethanolysis and methanolysis of Jatropha crucas oil

Zirconium impregnated (5-20 wt.%) calcium oxide (Zr/Ca0) was prepared by a simple wet chemical method followed by calcination up to 900 C. The prepared Zr/CaO was employed as a heterogeneous catalyst for the transesterification of Jatropha crucas oil with ethanol and methanol for the production of fatty acid ethyl and methyl esters, respectively. The catalysts were characterized by powder X-ray diffraction, Fourier transforminfrared spectroscopy, Brunauer-Emmett-Teller surface Area measurement, scanning electron microscopy, transmission electron microscopy techniques and basic strength of the catalyst were established by acid-base titration. The catalytic activity was found to be a function of basic sites which in turn depend on calcination temperature and zirconium concentration. The catalyst with 15 wt.% zirconium concentration and calcined at 700 degrees C, showed the highest catalytic activity among the prepared catalysts. A pseudo first order kinetic equation was applied to evaluate the kinetic parameters of Zr/CaO catalyzed transesterification. The activation energy (Ea) for the Zr/CaO catalyzed methanolysis and ethanolysis was found to be 29.8 kJ mol(-1) and 42.5 kJ mol(-1), respectively. The Koras-Nowak test was performed to demonstrate that catalytic activity was independent from the mass transport phenomenon and follows the kinetic regime. (C) 2013 Elsevier BY. All rights reserved.